Preheat the oven to 325°F (165°C).
Grease and flour or line two 8 inch (20 cm) round cake tins or one deep 8 inch (20 cm) round cake tin or a 9 x 13 inch (22 x 33 cm) pan.
Sift the flour, baking powder, baking soda, cocoa and caster sugar into a large bowl.
Using a wooden spoon, make a well in the centre of the sifted ingredients.
Add the sunflower oil, lightly beaten eggs, milk and golden syrup into the well.
Mix well with the wooden spoon until you have a smooth batter.
Pour the batter into the pan(s).
Bake for 20 to 30 minutes or until the top of the cake(s) spring back when touched lightly. (If you are using two 8 inch round pans or the 9 x 13 inch pan, the cake takes less time to bake than the one deep 8 inch round cake tin.) A skewer or toothpick inserted in the centre of the cake should come out clean.